[OT] Testing an SD card

[Josef Wolf]

On Fri, Aug 19, 2016 at 06:50:00AM +0200, Volker Wysk wrote:

> I've let your script run over night, and it still didn't finish. The SD card is 
> 64 GB large.
> 
> The output in the (small) part which is visible in the xterm, and which can be 
> scrolled back, didn't contain any error messages.

That there are no errors doesn't mean anything AS LONG AS IT HAS NOT FINISHED.

You need to undestand that there are two passes:

First pass will fill the SD with random data. NO error detection is done
during this pass

Second pass verifies taht what was written can be read back. Only when the
first pass is finished, you can tell whether there were any errors.

During operation, there is progress output:
- w=first, r=second pass.
- amount of read/written data
- duration of the pass

>From this output, you can deduce how long it will run.

-- 
Josef Wolf
jw at raven.inka.de